SNAKE-BITES AND POISONOUS FISHES. 117 



tioned, except the toxin produced by diphtheria. (Sidney Martin.) In all 

 cases, however, these albumoses, though differing greatly in intensity of 

 action, yet when gaining access to the blood produce certain toxic effects; 

 hence the antitoxic principle which now underlies the treatment of snake- 

 bite, etc. The poisonous properties of peptone are becoming much more 

 recognized through the work of Prof. Wright and others ; it is an important 

 fact to deal with in the preparation of antitoxic and prophylactic serums. 



It has been shown by Martin and Gavan Smith that when dried venom 

 is heated, it separates out into an albumen coagulated by heat, 70°-80° 0., 

 and a filtrate non-coagulable at any temperature, its action being, however, 

 destroyed by boiling. 



It has been further shown by Calmette that the albumen thus coagulated 

 out has little toxic power, but that the filtrate, when dialysed out in a 

 current of sterile water for twenty-four hours, gives a solution which, on 

 being dried in vacuo, forms a brownish amorphous powder forty times more 

 toxic than ordinary venom. 



The amount of the coagulable and non-coagulable proteids varies in amount 

 and proportion in different classes of snakes ; thus in the Colubrine there is 

 a large amount of non-coagulable poison, in the Viperine there is a very con- 

 siderable quantity of the coagulable ; on this difference depends to a large 

 extent the variation of the symptoms produced by individual snakes. This 

 is nevertheless only one of degree, as the toxic effects of the non-coagulable 

 poison are veiy much the same in all, acting principally on the nerve centres, 

 producing death by paralysing the respiratory centre in the medulla. The 

 coagulable proteid acts chiefly on the blood-vessels and heart, being a 

 powerful local irritant. 



Cobra poison, which, as before stated, is rich in the non-coagulable pro- 

 teid, kills by producing asphyxia, the heart beating after respiration has 

 stopped ; hence the use of artificial respiration in the treatment. 



Rattlesnake venom is rich in the coagulable proteid, producing disastrous 

 effects on the blood-vessels and heart. 



Australian snakes show a good deal of both, and have an intermediate 

 action. 



Sir Joseph Fayrer found that cobra venom killed without destroying the 

 coagulabdity of the blood, whilst Daboia (viper) poison caused complete and 

 permanent fluidity, the blood of the animals so killed being excessively toxic. 



Cobra poison produces little change in the pupil, Daboia widely dilates ; 

 salivation is a constant symptom of the former, rare in the latter. 



When experimenting with venoms, Calmette and others at Lille use only 

 the non-coagulable proteid, by which means they get rid of the intense local 

 reaction of the second proteid, and as the chief toxic properties are in the 

 former, the physiological effects of the venom are better thus watched. He 

 also at once mixes up the venoms of all his snakes, from the sum total of 

 which he obtains his dried toxin for experimental purposes. 



